org.apache.pig.newplan.logical.relational

Class LogicalRelationalOperator

java.lang.Object

org.apache.pig.newplan.Operator

org.apache.pig.newplan.logical.relational.LogicalRelationalOperator

Direct Known Subclasses:

LOCogroup, LOCross, LOCube, LODistinct, LOFilter, LOForEach, LOGenerate, LOInnerLoad, LOJoin, LOLimit, LOLoad, LONative, LORank, LOSort, LOSplit, LOSplitOutput, LOStore, LOStream, LOUnion

public abstract class LogicalRelationalOperator
extends Operator

Logical representation of relational operators. Relational operators have a schema.

Field Summary

Fields

Modifier and Type	Field and Description
protected String	alias
protected int	lineNum
protected String	mCustomPartitioner Name of the customPartitioner if one is used, this is set to null otherwise.
protected HashSet<Integer>	mPinnedOptions A HashSet to indicate whether an option (such a Join Type) was pinned by the user or can be chosen at runtime by the optimizer.
protected int	requestedParallelism
protected LogicalSchema	schema

Fields inherited from class org.apache.pig.newplan.Operator

annotations, hashPrime, location, name, plan

Constructor Summary

Constructors

Constructor and Description
LogicalRelationalOperator(String name, OperatorPlan plan)
LogicalRelationalOperator(String name, OperatorPlan plan, int rp)

Method Summary

Modifier and Type	Method and Description
protected boolean	checkEquality(LogicalRelationalOperator other) Do some basic equality checks on two relational operators.
static void	fixDuplicateUids(List<LogicalSchema.LogicalFieldSchema> fss) In the case of an operation which manipualtes columns (such as a foreach or a join) it is possible for multiple columns to have been derived from the same column and thus have duplicate UID's.
String	getAlias() Get the alias of this operator.
String	getCustomPartitioner()
int	getLineNumber() Get the line number in the submitted Pig Latin script where this operator occurred.
int	getRequestedParallelism() Get the requestedParallelism for this operator.
abstract LogicalSchema	getSchema() Get the schema for the output of this relational operator.
boolean	isPinnedOption(Integer opt)
void	neverUseForRealSetSchema(LogicalSchema schema) Only to be used by unit tests.
void	pinOption(Integer opt)
void	resetSchema() Reset the schema to null so that the next time getSchema is called the schema will be regenerated from scratch.
void	resetUid() Erase all cached uid, regenerate uid when we regenerating schema.
void	setAlias(String alias)
void	setCustomPartitioner(String customPartitioner)
void	setRequestedParallelism(int parallel)
void	setSchema(LogicalSchema schema)
String	toString()

Methods inherited from class org.apache.pig.newplan.Operator

accept, annotate, getAnnotation, getLocation, getName, getPlan, isEqual, removeAnnotation, setLocation, setPlan

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

schema

protected LogicalSchema schema

requestedParallelism

protected int requestedParallelism

alias

protected String alias

lineNum

protected int lineNum

mCustomPartitioner

protected String mCustomPartitioner

Name of the customPartitioner if one is used, this is set to null otherwise.

mPinnedOptions

protected HashSet<Integer> mPinnedOptions

A HashSet to indicate whether an option (such a Join Type) was pinned by the user or can be chosen at runtime by the optimizer.

Constructor Detail

LogicalRelationalOperator

public LogicalRelationalOperator(String name,
                                 OperatorPlan plan)

Parameters:

name - of this operator

plan - this operator is in

LogicalRelationalOperator

public LogicalRelationalOperator(String name,
                                 OperatorPlan plan,
                                 int rp)

Parameters:

name - of this operator

plan - this operator is in

rp - requested parallelism

Method Detail

getSchema

public abstract LogicalSchema getSchema()
                                 throws FrontendException

Get the schema for the output of this relational operator. This does not merely return the schema variable. If schema is not yet set, this will attempt to construct it. Therefore it is abstract since each operator will need to construct its schema differently.

Returns:

the schema

Throws:

FrontendException

setSchema

public void setSchema(LogicalSchema schema)

resetSchema

public void resetSchema()

Reset the schema to null so that the next time getSchema is called the schema will be regenerated from scratch.

resetUid

public void resetUid()

Erase all cached uid, regenerate uid when we regenerating schema. This process currently only used in ImplicitSplitInsert, which will insert split and invalidate some uids in plan

getRequestedParallelism

public int getRequestedParallelism()

Get the requestedParallelism for this operator.

Returns:

requestedParallelsim

getAlias

public String getAlias()

Get the alias of this operator. That is, if the Pig Latin for this operator was 'X = sort W by $0' then the alias will be X. For store and split it will be the alias being stored or split. Note that because of this this alias is not guaranteed to be unique to a single operator.

Returns:

alias

setAlias

public void setAlias(String alias)

setRequestedParallelism

public void setRequestedParallelism(int parallel)

getLineNumber

public int getLineNumber()

Get the line number in the submitted Pig Latin script where this operator occurred.

Returns:

line number

neverUseForRealSetSchema

public void neverUseForRealSetSchema(LogicalSchema schema)

Only to be used by unit tests. This is a back door cheat to set the schema without having to calculate it. This should never be called by production code, only by tests.

Parameters:

schema - to set

checkEquality

protected boolean checkEquality(LogicalRelationalOperator other)
                         throws FrontendException

Do some basic equality checks on two relational operators. Equality is defined here as having equal schemas and predecessors that are equal. This is intended to be used by operators' equals methods.

Parameters:

other - LogicalRelationalOperator to compare predecessors against

Returns:

true if the isEquals() methods of this node's predecessor(s) returns true when invoked with other's predecessor(s).

Throws:

FrontendException

toString

public String toString()

Overrides:

toString in class Object

getCustomPartitioner

public String getCustomPartitioner()

setCustomPartitioner

public void setCustomPartitioner(String customPartitioner)

pinOption

public void pinOption(Integer opt)

isPinnedOption

public boolean isPinnedOption(Integer opt)

fixDuplicateUids

public static void fixDuplicateUids(List<LogicalSchema.LogicalFieldSchema> fss)

In the case of an operation which manipualtes columns (such as a foreach or a join) it is possible for multiple columns to have been derived from the same column and thus have duplicate UID's. This detects that case and resets the uid. See PIG-3020 and PIG-3093 for more information.

Parameters:

fss - a list of LogicalFieldSchemas to check the uids of